The hydrogen fuel system leak recall affects 2019–2020 Nexo models, where a defective check valve or filler neck connection can cause a slow hydrogen leak. Symptoms include a 'Check fuel system' warning and a hissing sound near the fuel filler port when parked, creating a fire or explosion risk and potential automatic shutdown. Out-of-warranty repair typically costs around $1,850 for replacing the filler neck and valve assembly.

The fuel cell system fault, most common on 2019–2021 Nexo models, is due to failure of the air compressor bearings or coolant pump. It triggers a 'Check Fuel Cell System' warning, sudden loss of acceleration, and limp mode, possibly with a loud whine from the compressor before failure. Replacement of the air compressor costs approximately $5,250, with additional costs if the coolant pump also needs replacement.

2019–2022 Nexo models suffer from premature 12V battery failure due to BMS logic that fails to keep the battery charged when parked, worsened by telematics drain. Symptoms include a dead battery, 'Battery discharge' warning, and inability to open the hydrogen fill port, leaving you stranded. A replacement AGM battery and BMS re-flash typically costs about $525.

The hydrogen fill door actuator fails on 2019–2023 Nexo models due to moisture or cycling wear, causing the door not to open or close properly. This triggers a 'Fuel door malfunction' warning and prevents refueling. Dealer replacement of the actuator and lock assembly costs around $265.